What is the best way to experience Dev Deepawali at Varanasi?

The most iconic way to experience Dev Deepawali is from a boat on the Ganga, looking toward the illuminated western bank. Book a boat in advance (a day or two before the festival) directly from the ghat boatmen. Arriving by 5:00 PM to witness the lamp-lighting at dusk, then continuing into the evening Ganga Aarti at Dashashwamedh Ghat, gives you the full arc of the celebration.